Dennis Water District
EPA ID: MA4075000 · 65,000 people served · 5 ZIP codes
ZipCheckup's reading of EPA records for Dennis Water District (MA4075000): no drinking-water violations recorded since 2021. Violation-free in EPA records - Dennis Water District, 65,000 residents served.
Data: EPA SDWIS
Service Area Map
Coverage area for Dennis Water District Source: EPA SDWIS service area boundaries.
Service area boundary - average Home Safety grade of mapped ZIPs: B
Demographics of ZIP Codes Served
The ZIP codes associated with Dennis Water District have a median household income of $90,662 and about 14,780 residents live in those ZIP codes (Census; not the number of people this system supplies). Approximately 78% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Dennis Water District's water is classified in EPA records as a groundwater source. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
Infrastructure Risk
PFAS in ZIP Codes This System Serves
PFAS ("forever chemicals") have been reported in samples from water systems associated with the ZIP codes in this system's area. These results can come from other water systems serving the same ZIP codes; check the UCMR5 section for any results reported for this system. 8 detections recorded.
Comparable Water Systems
Similar-sized systems in Massachusetts
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Dennis Water District (EPA ID: MA4075000) is a community water system in Massachusetts that serves approximately 65,000 people from groundwater sources.
This system provides water to 5 ZIP codes across 5 communities.
ZIP-Area Home Safety Context: B (83/100)
This is the average Home Safety Score for 4 of 5 service-area ZIP codes with all required score domains observed. It is not a grade for the water utility.
Model 4.0.0 uses SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the UCMR 5 PFAS MCL screen, EPA radon zone, and annual EPA AirData AQI across three equally weighted domains. Missing required evidence suppresses the score.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| Below the reporting limit | No | 2023-12-31 |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
5 of 5 ZIP records with known zones are in EPA Radon Zone 2.
The EPA recommends testing all homes regardless of radon zone. County radon zones cannot replace an in-home radon test.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by MA or modeled from parcel and building-footprint data.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View available EPA compliance records for Dennis Water District (MA4075000) on EPA.gov.
Frequently Asked Questions
Is Dennis Water District water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Dennis Water District in the inclusive 2021-2026 record-year window. This is a compliance-record finding, not a guarantee about water at a specific tap.
How many people does Dennis Water District serve?
Dennis Water District serves approximately 65,000 people across 5 ZIP codes in Massachusetts.
Where does Dennis Water District get its water?
The primary water source is groundwater.
Federal UCMR5 PFAS Monitoring: Detected
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). PFAS compounds were detected; the table compares each one with the EPA MCL where one exists (April 2024 rule, compliance required from 2029) and with this state's enforceable standard where one exists.
MA enforces a limit of 20 ppt for the combined sum of six PFAS (PFOA, PFOS, PFHxS, PFNA, PFHpA and PFDA). The table shows each compound's highest result, which can come from different samples, so it is not compared with that combined limit; the water system's compliance reports give the combined result.
EPA's April 2024 PFAS rule sets MCLs of 4 ppt for PFOA and PFOS and 10 ppt for PFHxS, PFNA and HFPO-DA (GenX); water systems must comply from 2029. Other PFAS compounds have no individual federal MCL. A state standard is shown only where this system's state has its own enforceable PFAS limit. Detection results are EPA UCMR5 samples, not a measurement at your tap.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Dennis Water District, MA: Serves 65K People. https://zipcheckup.com/water-system/ma4075000/
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